Notes about the aerial photographs

General Notes

Geographic Alignment

Because of the imprecise method of setting up photographs for scanning by hand, no claim is made to a strict alignment between geographic or magnetic North and the vertical direction of the presented images.

Image Boundaries

The boundaries of the presented images, which are viewable by quickly double-clicking the right mouse button on the area of interest, are only approximations. Adjacent areas of a particular point of interest may need to be viewed for completeness.

1951 Notes

Quality of Images

The 1951 set of aerial photographs was scanned at 300 dpi which has resulted in more graininess than in the originals. Scanning, even on a large format scanner such as the Vidar TruScan 500 on which these photos were scanned, is an inexact process and some graininess and distortion is to be expected. Also, the process of converting the images to a browser compatible format resulted in an increase in image size. Therefore, the original scale of the photos, as inexact as it must have been, has been lost. No claim to a particular scale is then made for the images presented.

Document Imperfections

The photographs from which the images here presented are a half century old. In many cases, tears and other flaws have been imported through the scanning process. Caution should be exercised in order that these imperfections not be misconstrued as topographic features.

Overlap

The viewable area of each photograph which was scanned was somewhat less than the maximum available. This policy was adopted both to eliminate a good deal of the raggedness of the original photographs and because of hardware limitations associated with the scanning process itself. While there should be adequate overlap in the presented images, more in the north-south direction than east-west, some additional scanning had to be done to compensate for less than adequate overlap in the originals. While care has been taken to insure that as much of the County has been covered as possible, there may be some cases in which this obective was not achieved.

Completeness

As with any other historical document, time and use has had an effect on the availability of the original photographs. There are a small number of missing photographs. In each of these cases, notification is provided to that effect.

1920's Notes

Quality of Images

The aerial photographs from the 1926-1929 set were scanned at 500 dpi. Although considerably better than the 1951 set, there is still more graininess than in the originals. Some of this is due to a similar enlargement of the image by a factor of a little over two. On all plates a scale is given of 600 feet to the inch. In actuality, the image on your screen has a scale of about 600 feet to two and one eighth inches.

Document Imperfections

There are two sources of imperfection in the 1920's set of photos. First, most of the plates which were scanned were actually constructed from a number of photos of a particular area. In some cases, the lines showing the separation between these original photos is visible in the resulting plate. Second, the originals of these images were used over the years in various construction projects and, as a result, were marked up with pen or pencil. In either case, care must be exercised not to construe man-made graphical features as either man-made or natural geographic features.

Overlap

The plates were designed so as to provide about 1/2"(=~300ft.) of overlap on each border where an adjacent photograph exists. These are clearly indicated on the presented images by a white line parallel to, and about one inch from, the edge of the plate. Also, on those plates which border on other plates in this manner, an edge connector specifiying the bordering plate's letter-number designator can be found in this border area. The letter-number designator of the current plate can be found both in the title at the top of the screen and in the upper right-hand corner of the plate. The edge connector designators on each plate have been enabled so that left-clicking on the designator will take you to that plate.

Completeness

One of the marvels of this very old and unique set of aerial photographs is the completeness with which Erie County is covered. Additionally, coverage of Fort Erie, Ontario, Niagara Falls, Ontario and Niagara Falls, New York is also included.